CN114200829B - A pseudo-closed-loop high-precision speed control method for supersonic large maneuvering targets - Google Patents

Abstract

The invention provides a supersonic large maneuvering targetThe high-precision speed control method based on the pseudo-closed loop aims to provide a high-precision pseudo-closed loop speed control method in a cruising section by adopting a liquid rocket engine with discontinuous thrust adjustment as a large maneuvering target of power. The method comprises the steps of firstly predicting cruising resistance of a section through a mathematical model of a large maneuvering target; and then according to the predicted resistance D _yc 3 thrust combination strategies are designed; because the engine thrust is established and the engine is declined and has response time, in order to ensure the high-precision control of the cruising speed, the threshold correction value of the engine on-off is designed. The flight test results demonstrate the effectiveness of this method.

Description

A pseudo-closed-loop high-precision velocity control method for supersonic large maneuvering targets

technical field

The present invention relates to a speed control method of a supersonic large maneuvering target, in particular to a high-precision speed control method based on a pseudo-closed loop during the cruising process of a supersonic large maneuvering target powered by a liquid rocket engine whose thrust cannot be continuously adjusted .

Background technique

The Skylark supersonic large maneuvering target is a high-performance target jointly developed by Northwestern Polytechnical University and Xi'an Aerospace Power Research Institute. Weapon system development, finalization, qualification, and tactical training of pilots provide high-performance air targets. The target can achieve cruise flight within a wide speed envelope of 0.8 to 1.6 Ma in a large airspace of 8 to 14 km, and at the same time can achieve a stable and large overload maneuver of not less than 6g within the full envelope. In order to achieve the ability to simulate the supersonic cruise and maneuvering flight of the fourth-generation fighter, the aero-engine cannot meet the design requirements during the target development stage, which makes the large maneuvering target only use liquid rocket engine as power in the selection of power system.

However, the characteristic of the liquid rocket engine is that the thrust cannot be continuously adjusted during the flight. The Skylark large maneuvering target has two liquid rocket engines, and each liquid rocket engine has 3 gears, respectively 600/1000/1200N As well as 2000/2500/2800N, the gears of the two engines need to be set before launch and cannot be changed after launch. The combination of the thrust gears of the two engines can cover any profile within the full flight envelope. Since the speed of the fourth-generation aircraft is stable and controllable during cruising flight, in order to realistically simulate the flight performance of the fourth-generation aircraft, there is a high requirement for the control accuracy of the flight speed of large maneuvering targets, which needs to be controlled within a high-precision range. Therefore, how to ensure the high-precision control of the speed under the condition that the thrust cannot be continuously adjusted when the large maneuvering target is cruising is a key technology for the development of the large maneuvering target.

Contents of the invention

Aiming at the speed control problem of the target whose thrust cannot be continuously adjusted, the present invention proposes a high-precision pseudo-closed-loop speed control method based on cruise resistance prediction. Before the mission starts, the cruise speed is first set according to the accuracy requirements of the mission for the cruise speed. Control the upper and lower thresholds Ma _Poff and Ma _Pon , and at the same time determine the gear combinations P1 and P2 of the two engines and the cruise engine combination strategy based on the predicted resistance of the cruise profile, and set the selected gear on the ground. After launch, when the target flies to the mission profile and meets the cruise engine start-up conditions, the corresponding engine is turned on according to the cruise engine combination strategy. When the speed exceeds the cruise speed upper limit Ma _Poff , the engine is turned off, and then the speed decreases. When the speed is lower than the cruise speed When the Ma _Pon is lowered, turn on the engine. Since the engine thrust build-up time is different, in order to improve the control accuracy, the actual switch threshold value of the engine is corrected Ma′ _Poff , Ma′ _Pon .

The technical idea of the present invention is: based on the task-based speed control accuracy requirements, set the speed control threshold for the cruise segment of the large maneuvering target, design the engine combination strategy for the target cruise segment, consider the engine thrust establishment time, and modify the speed control threshold. The corresponding engine is turned on or off according to the threshold to realize high-precision speed control in the target cruising segment.

The present invention is a pseudo-closed-loop high-precision speed control method for a supersonic large maneuvering target, comprising the following steps:

Step 1: Build a target model and predict profile resistance

After selecting the mission profile H _c , Mac _c , first calculate the equilibrium angle of attack α _b of the profile,

ρ(H_c)为大气密度，是高度的函数，H_c为靶标巡航高度；V_W为靶标的对风速度，V_W＝Ma_WV_v(H_c)，Ma_W为靶标的对风马赫数，

Ma_c为靶标巡航时相对地的马赫数，Ma_wind为靶标巡航高度H_c下的风场马赫数，V_v(H_c)为靶标巡航剖面的音速。g＝9.8，s为靶标的参考面积，/>

为升力对攻角的偏导，α为靶标的攻角。In the above formula, q is the target dynamic pressure,

ρ(H _c ) is the atmospheric density, which is a function of height, H _c is the cruise height of the target; V _W is the wind speed of the target, V _W = Ma _W V _v (H _c ), Ma _W is the wind Mach of the target number,

Ma _c is the Mach number relative to the ground when the target is cruising, Ma _wind is the Mach number of the wind field at the target cruising altitude H _c , and V _v (H _c ) is the sound velocity of the target cruising profile. g=9.8, s is the reference area of the target, />

is the deflector of the lift to the angle of attack, and α is the angle of attack of the target.

Taking β=0, the expression of the resistance D _yc during the cruise of the predicted mission profile is:

D _yc ＝qsC _D (Ma _W ,α _b ,β) (2)

In the formula, q is the dynamic pressure of the target, s is the reference area of the target, _CD is the aerodynamic drag coefficient of the target, Ma _W is the Mach number of the target against the wind, α _b is the equilibrium angle of attack of the target, and β is the sideslip of the target angle, where β=0.

Step 2: Design thrust combination strategy

The large maneuvering target C _D includes 2 liquid rocket engines, define the small thrust engine as P1, and the large thrust engine as P2, P1 includes 3 levels of thrust, respectively 600/1000/1200N, P2 includes 3 levels of thrust, respectively 2000/2500N /2800N. The thrust combination strategies for designing large maneuvering targets only for cruising tasks are as follows:

(1) Strategy 1: Cruise with 1 P1

If the predicted cruising resistance D _yc <1200N, then only one P1 engine is used for cruising, and the thrust gear of the selected P1 engine satisfies T _1c >D _yc ;

(3) Strategy 2: Cruise with P1 and P2, P1 is the main cruise engine

If the predicted cruising resistance is 1200N≤D _yc <2000N, P1 and P2 need to be turned on at the same time for cruising, P1 is the main cruising engine, and it will be turned on continuously during cruising, select the gear position T _1c = 1200N, and select the gear position T _2c = 2800N for P2;

(3) Strategy 3: Cruise with P1 and P2, P2 is the main cruise engine

If the predicted cruising resistance is 2000N≤D _yc <4000N, P1 and P2 need to be turned on at the same time for cruising, P2 is the main cruising engine, and the minimum gear T _1c , T _2c that satisfies T _1c +T _2c >D _yc is selected.

Step 3: Design speed pseudo-closed-loop control strategy

First, according to the requirements of the current mission profile for speed control accuracy σ _Ma , set the upper and lower thresholds Ma _Poff and Ma _Pon of cruise speed control, where Ma _Poff = _Mac +σ _Ma , Ma _Pon = Mac _c -σ _Ma .

Since the thrust of the engines P1 and P2 of the large maneuvering target cannot be continuously adjusted, the pseudo-closed-loop control strategy of the speed of the target is designed according to the thrust combination strategy in step 2 as follows:

(1) Strategy 1: Thrust Combination Strategy 1

When the target enters the profile and meets the engine start-up conditions, turn on the P1 engine and judge the current cruising speed of the target. When it is greater than the upper threshold Ma _Poff , turn off the _P1 engine; after the P1 engine is turned off, the target speed gradually decreases. , turn on the P1 engine; and so on until the end of the cruise mission.

(2) Strategy 2: Thrust Combination Strategy 2

When the target enters the profile and meets the engine start-up conditions, turn on the P1 and P2 engines to judge the current cruising speed of the target. When it is greater than the upper threshold Ma _Poff , turn off the P2 engine, and the P1 engine remains on; Small, when it is less than the lower threshold Ma _Pon , turn on the P2 engine; and so on until the end of the cruise task.

(3) Strategy 3: Thrust Combination Strategy 3

When the target enters the profile and meets the engine start-up conditions, turn on the P1 and P2 engines to judge the current cruising speed of the target. When it is greater than the upper threshold Ma _Poff , turn off the P1 engine, and the P2 engine remains on; Small, when it is less than the lower threshold Ma _Pon , turn on the P1 engine; and so on until the end of the cruise task.

Step 4: Establish the thrust on/off model, and correct the speed pseudo-closed-loop control strategy threshold

(1) Thrust boot model

Through the thermal test of the power system, the statistics show that the thrust start-up model of the target 2 thrust engines with a total of 6 thrust gears is:

In the above formula, T _Cij is the theoretical thrust, τ _Fij is the response time of the solenoid valve, which means the time from receiving the command to start the thrust to the opening of the solenoid valve, τ _Oij is the establishment time corresponding to each thrust, where i represents the serial number of the engine, i=1,2, j represents the serial number of the thrust gear, j=1,2,3, for example, T _1c1 is the first thrust gear of the first engine, ie T _C11 =600N.

It can be seen from the above formula that within the time τ _Fij after the engine is turned on, the solenoid valve is closed to open, and the thrust is 0 during this period; within the time τ _Fij +τ _Oij , the engine thrust gradually increases from 0 to the theoretical Thrust, the speed of the target in this interval tends to decrease first, and at time t when the target T _ij (t) is equal to the resistance D _b at the current moment, the speed of the target begins to increase gradually. Therefore, if the engine is turned on at the lower threshold Ma _Pon , the cruise speed of the target will be less than Ma _Pon during the thrust building process. To sum up, in order to improve the control accuracy of cruising speed, the power-on threshold is modified as follows:

Ma' _Pon ＝Ma _Pon -δ _Mon (4)

In the above formula, δ _Mon is the correction value of the upper limit of speed control, and the calculation method is as follows:

In the above formula, the thrust at time t _m T _ij (t _m )=D _yc , τ _Fij <t _m <τ _Fij +τ _Oij .

(2) Thrust shutdown model

Through the thermal test of the power system, the statistics show that the thrust shutdown model of the target 2 thrust engines with a total of 6 thrust gears is:

In the above formula, T _Cij is the theoretical thrust, τ _Fij is the closing response time of the solenoid valve, which is consistent with the opening response time of the solenoid valve, τ _Cij is the time for each thrust to drop from 100% to 0, where i represents the engine serial number, and j represents the thrust Gear number, for example, T _Cij is the first thrust gear of the first engine, that is, T _1c1 =600N.

It can be seen from the above formula that within the time τ _Fij after the engine is turned on, the solenoid valve is opened to close, and the thrust during this period is the theoretical thrust T _icj ; within the time τ _Fij +τ _Cij , the engine thrust gradually changes from the theoretical thrust Decrease to 0, in this range, the speed of the target increases first, and at time t when the target T _Gij (t) is equal to the resistance D _b at the current moment, the speed of the target begins to decrease gradually. Therefore, if the engine is turned off at the upper threshold Ma _Poff , the cruise speed of the target will be greater than Ma _Poff during the thrust off process. To sum up, in order to improve the control accuracy of cruising speed, the shutdown threshold value is modified as follows:

Ma′ _Poff ＝ Ma _Poff -δ _Moff (7)

In the above formula, δ _Moff is the correction value of the lower limit of speed control, and the calculation method is as follows:

In the above formula, the thrust T _Gij (t _n ) at time t _n = D _yc , τ _Fij <t _n <τ _Fij +τ _Cij .

The beneficial effects of the present invention are as follows: a large maneuvering target powered by a liquid rocket engine whose thrust cannot be continuously adjusted, and based on a pseudo-closed-loop high-precision speed control method during the cruising process, can realize the high-precision speed control of the target while cruising and flying indicator requirements. The working mode of the present invention is simple and reliable.

Description of drawings

Fig. 1 is a structural diagram of the open-loop speed control of a large maneuvering target in the present invention.

Fig. 2 is a structural diagram of the pseudo closed-loop speed control of a large maneuvering target in the present invention.

Fig. 3 is two engine command curves of the large maneuvering target flight test cruising section of the present invention.

Fig. 4 is the P2 engine command and the thrust chamber chamber pressure curve of the large maneuvering target flight test of the present invention.

Fig. 5 is the Mach number curve of the flight test of the large maneuvering target of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described with reference to accompanying drawings 1-4.

The invented large maneuvering target cruise task pseudo closed-loop speed control method includes the following steps:

Step 1: Build a target model and predict profile resistance

After selecting the mission profile H _c , Mac _c , first calculate the equilibrium angle of attack α _b of the profile,

ρ为大气密度，V_W为靶标的对风速度，s为靶标的参考面积，/>

为升力对攻角的偏导。In the above formula, H _c is the target cruising altitude, _Mac is the target cruising speed, refers to the relative Mach number, m is the mass of the target, g=9.8, q is the target dynamic pressure,

ρ is the atmospheric density, V _W is the wind speed of the target, s is the reference area of the target, />

is the deflector of the lift force with respect to the angle of attack.

Take β=0 to predict the resistance during mission profile cruise:

D _yc ＝qsC _D (Ma _W ,α _b ,β) (10)

Step 2: Design thrust combination strategy

The large maneuvering target includes 2 liquid rocket engines, define the small thrust engine as P1, and the large thrust engine as P2, P1 includes 3 gears of thrust, respectively 600/1000/1200N, P2 includes 3 gears of thrust, respectively 2000/2500/ 2800N. The thrust combination strategies for designing large maneuvering targets only for cruising tasks are as follows:

(1) Strategy 1: Cruise with 1 P1

If the predicted cruising resistance D _yc <1200N, then only one P1 engine is used for cruising, and the thrust gear of the selected P1 engine satisfies T _1c >D _yc ;

(3) Strategy 2: Cruise with P1 and P2, P1 is the main cruise engine

If the predicted cruising resistance is 1200N≤D _yc <2000N, P1 and P2 need to be turned on at the same time for cruising, P1 is the main cruising engine, and it will be turned on continuously during cruising, select the gear position T _1c = 1200N, and select the gear position T _2c = 2800N for P2;

(3) Strategy 3: Cruise with P1 and P2, P2 is the main cruise engine

If the predicted cruising resistance is 2000N≤D _yc <4000N, P1 and P2 need to be turned on at the same time for cruising, P2 is the main cruising engine, and the minimum gear T _1c , T _2c that satisfies T _1c +T _2c >D _yc is selected.

Step 3: Design speed pseudo-closed-loop control strategy

First, according to the requirements of the current mission profile for speed control accuracy σ _Ma , set the upper and lower thresholds Ma _Poff and Ma _Pon of cruise speed control, where Ma _Poff = _Mac +σ _Ma , Ma _Pon = Mac _c -σ _Ma .

Since the thrust of the engines P1 and P2 of the large maneuvering target cannot be continuously adjusted, the pseudo-closed-loop control strategy of the speed of the target is designed according to the thrust combination strategy in step 2 as follows:

(1) Strategy 1: Thrust Combination Strategy 1

When the target enters the profile and meets the engine start-up conditions, turn on the P1 engine and judge the current cruising speed of the target. When it is greater than the upper threshold Ma _Poff , turn off the _P1 engine; after the P1 engine is turned off, the target speed gradually decreases. , turn on the P1 engine; and so on until the end of the cruise mission.

(2) Strategy 2: Thrust Combination Strategy 2

When the target meets the engine start-up conditions after entering the profile, turn on the P1 and P2 engines in turn to judge the current cruising speed of the target. When it is greater than the upper threshold Ma _Poff , turn off the P2 engine, and the P1 engine remains on; Decrease, when it is less than the lower threshold Ma _Pon , turn on the P2 engine; and so on until the end of the cruise task.

(3) Strategy 3: Thrust Combination Strategy 3

When the target enters the profile and meets the engine start-up conditions, turn on the P1 and P2 engines in turn to judge the current cruising speed of the target. When it is greater than the upper threshold Ma _Poff , turn off the P1 engine, and the P2 engine remains on; Decrease, when it is less than the lower threshold Ma _Pon , turn on the P1 engine; and so on until the end of the cruise task.

Step 4: Establish the thrust on/off model, and correct the speed pseudo-closed-loop control strategy threshold

(1) Thrust boot model

Through the thermal test of the power system, the statistics show that the thrust start-up model of the target 2 thrust engines with a total of 6 thrust gears is:

In the above formula, T _Cij is the theoretical thrust, τ _Fij is the response time of the solenoid valve, which means the time from receiving the command to start the thrust to the opening of the solenoid valve, and τ _Oij is the establishment time corresponding to each thrust, where i represents the serial number of the engine, i=1, 2, j represents the serial number of the thrust gear, j=1, 2, 3, for example, T _1c1 is the first thrust gear of the first engine, ie T _C11 =600N.

It can be seen from the above formula that within the time τ _Fij after the engine is turned on, the solenoid valve is closed to open, and the thrust is 0 during this period; within the time τ _Fij +τ _Oij , the engine thrust gradually increases from 0 to the theoretical Thrust, in this range, the speed of the target decreases first, and at time t when the target T _ij (t) is equal to the resistance D _b at the current moment, the speed of the target begins to increase gradually. Therefore, if the engine is turned on at the lower threshold Ma _Pon , the cruise speed of the target will be less than Ma _Pon during the thrust building process. To sum up, in order to improve the control accuracy of cruising speed, the power-on threshold is modified as follows:

Ma′ _Pon ＝Ma _Pon -δ _Mon (12)

In the above formula, δ _Mon is the correction value of the upper limit of speed control, and the calculation method is as follows:

In the above formula, the thrust at time t _m T _ij (t _m )=D _yc , τ _Fij <t _m <τ _Fij +τ _Oij .

(2) Thrust shutdown model

Through the thermal test of the power system, the statistics show that the thrust shutdown model of the target 2 thrust engines with a total of 6 thrust gears is:

In the above formula, T _Cij is the theoretical thrust, τ _Fij is the closing response time of the solenoid valve, which is consistent with the opening response time of the solenoid valve, τ _Cij is the time for each thrust to drop from 100% to 0, where i represents the engine serial number, and j represents the thrust Gear number, for example, T _Cij is the first thrust gear of the first engine, that is, T _1c1 =600N.

It can be seen from the above formula that within the time τ _Fij after the engine is turned on, the solenoid valve is opened to close, and the thrust during this period is the theoretical thrust T _icj ; within the time τ _Fij +τ _Cij , the engine thrust gradually changes from the theoretical thrust Decrease to 0, in this range, the speed of the target increases first, and at time t when the target T _Gij (t) is equal to the resistance D _b at the current moment, the speed of the target begins to decrease gradually. Therefore, if the engine is turned off at the upper threshold Ma _Poff , the cruise speed of the target will be greater than Ma _Poff during the thrust off process. To sum up, in order to improve the control accuracy of cruising speed, the shutdown threshold value is modified as follows:

Ma′ _Poff ＝ Ma _Poff -δ _Moff (15)

In the above formula, δ _Moff is the correction value of the lower limit of speed control, and the calculation method is as follows:

In the above formula, the thrust T _Gij (t _n ) at time t _n = D _yc , τ _Fij <t _n <τ _Fij +τ _Cij .

The method is verified by flight test. For the embodiment, the parameters of the method designed in the present invention are selected as follows: H _c =9000, Mac _c =1.2, σ _Ma =0.05, and the predicted resistance D yc of the target obtained through modeling is D _yc =2200N; therefore, strategy (2) is selected, the gear The thrust combination of 1200N+2800N is selected, so the relevant parameters are selected as: τ _F23 = 0.04s, τ _O23 = 120ms, τ _C23 = 100ms, T _C23 = 2800N, from which Ma' _Pon = 1.153, Ma' _Poff = 1.248 .

The command curves of the two engines of the large maneuvering target are shown in Figure 3, the command and thrust chamber pressure curves of the P2 engine are shown in Figure 4, and the Mach number curve is shown in Figure 5. It can be seen from Figure 3 that at 28.14s the aircraft met the engine start-up conditions, the P1 engine was turned on, and then when the speed dropped to the lower limit, the P2 engine was turned on, and then the P2 engine was turned off when the speed increased to the upper limit. It can be seen from Figure 4 that during the flight test The response time of the solenoid valve of the P2 engine is 40ms, the room pressure build-up time is 110ms, and the room pressure drop time is 80ms, which is in good agreement with the prediction. It can be seen from Figure 5 that the Mach number ranges from 1.1503 to 1.2498Ma, which is in line with the expected value The deviation does not exceed 0.0003Ma, and the precision is high. It can be seen from the results that the method is effective and has high engineering value.

Claims (2)

1. a supersonic large maneuvering target is based on the high-precision speed control method of pseudo-closed loop, it is characterized in that, comprises the following steps: Step 1: Establish target model and predict section resistance; Step 2: Design thrust combination strategy; The large maneuvering target C _D includes 2 liquid rocket engines, define the small thrust engine as P1, and the large thrust engine as P2, P1 includes 3 levels of thrust, respectively 600/1000/1200N, P2 includes 3 levels of thrust, respectively 2000/2500N /2800N; Step 3: Design a speed pseudo-closed-loop control strategy; According to the requirements of the current mission profile for the speed control accuracy σ _Ma , set the upper and lower thresholds Ma _Poff and Ma _Pon of the cruise speed control, where Ma _Poff =Ma _c +σ _Ma , Ma _Pon =Ma _c -σ _Ma ; Step 4: Establish a thrust on/off model, and revise the speed pseudo-closed-loop control strategy threshold; In step 1, after selecting the mission profile H _c , Mac _c , first calculate the equilibrium angle of attack α _b of the profile,

In the above formula, q is the target dynamic pressure,

ρ(H _c ) is the atmospheric density, which is a function of height, H _c is the cruise height of the target; V _W is the wind speed of the target, V _W = Ma _W V _v (H _c ), Ma _W is the wind Mach of the target number,

Ma _c is the Mach number relative to the ground when the target is cruising, Ma _wind is the Mach number of the wind field at the target cruising height H _c , V _v (H _c ) is the sound velocity of the target cruising profile; g=9.8, s is the reference area of the target , />

is the deflector of the lift to the angle of attack, and α is the angle of attack of the target; Taking β=0, the expression of the resistance D _yc during the cruise of the predicted mission profile is: D _yc ＝qsC _D (Ma _W ,α _b ,β)(2) In the formula, q is the dynamic pressure of the target, s is the reference area of the target, _CD is the aerodynamic drag coefficient of the target, Ma _W is the Mach number of the target against the wind, α _b is the equilibrium angle of attack of the target, and β is the sideslip of the target angle, where β=0; In step 2, the thrust combination strategies for designing large maneuvering targets only for cruising tasks are as follows: Strategy 1: Cruise with 1 P1 If the predicted cruising resistance D _yc <1200N, then only one P1 engine is used for cruising, and the thrust gear of the selected P1 engine satisfies T _1c >D _yc ; Strategy 2: Cruise with P1 and P2, P1 is the main cruise engine If the predicted cruising resistance is 1200N≤D _yc <2000N, P1 and P2 need to be turned on at the same time for cruising, P1 is the main cruising engine, and it will be turned on continuously during cruising, select the gear position T _1c = 1200N, and select the gear position T _2c = 2800N for P2; Strategy 3: Cruise with P1 and P2, P2 is the main cruise engine If the predicted cruising resistance is 2000N≤D _yc <4000N, P1 and P2 need to be turned on at the same time for cruising, P2 is the main cruising engine, and the minimum gear T _1c , T _2c that satisfies T _1c +T _2c >D _yc is selected; In step 3, since the thrust of the engines P1 and P2 of the large maneuvering target cannot be continuously adjusted, the pseudo-closed-loop control strategy of the speed of the target is designed according to the thrust combination strategy of step 2 as follows: Strategy 1: Thrust Combination Strategy 1 When the target enters the profile and meets the engine start-up conditions, turn on the P1 engine and judge the current cruising speed of the target. When it is greater than the upper threshold Ma _Poff , turn off the _P1 engine; after the P1 engine is turned off, the target speed gradually decreases. , turn on the P1 engine; and so on until the end of the cruise mission; Strategy 2: Thrust Combination Strategy 2 When the target enters the profile and meets the engine start-up conditions, turn on the P1 and P2 engines to judge the current cruising speed of the target. When it is greater than the upper threshold Ma _Poff , turn off the P2 engine, and the P1 engine remains on; Small, when it is less than the lower threshold Ma _Pon , turn on the P2 engine; and so on until the end of the cruise task; Strategy 3: Thrust Combination Strategy 3 When the target enters the profile and meets the engine start-up conditions, turn on the P1 and P2 engines to judge the current cruising speed of the target. When it is greater than the upper threshold Ma _Poff , turn off the P1 engine, and the P2 engine remains on; Small, when it is less than the lower threshold Ma _Pon , turn on the P1 engine; and so on until the end of the cruise task; In step 4, the thrust boot model is: Through the thermal test of the power system, the statistics show that the thrust start-up model of the target 2 thrust engines with a total of 6 thrust gears is:

In the above formula, T _Cij is the theoretical thrust, τ _Fij is the response time of the solenoid valve, which means the time from receiving the command to start the thrust to the opening of the solenoid valve, τ _Oij is the establishment time corresponding to each thrust, where i represents the serial number of the engine, i=1,2, j represents the serial number of the thrust gear, j=1,2,3, such as T _1c1 is the first thrust gear of the first engine, that is T _C11 =600N; It can be seen from the above formula that within the time τ _Fij after the engine is turned on, the solenoid valve is closed to open, and the thrust is 0 during this period; within the time τ _Fij +τ _Oij , the engine thrust gradually increases from 0 to the theoretical Thrust, the speed change trend of the target in this interval is to decrease first, when the target T _ij (t) is equal to the resistance D _b at the current moment at time t, the speed of the target begins to increase gradually; therefore, if the engine is at the lower threshold Ma _Pon When the power is turned on, the cruise speed of the target will be less than Ma _Pon during the thrust establishment process; in order to improve the control accuracy of the cruise speed, the power-on threshold is corrected as follows: Ma' _Pon ＝Ma _Pon -δ _Mon (4) In the above formula, δ _Mon is the correction value of the upper limit of speed control, and the calculation method is as follows:

In the above formula, the thrust at time t _m T _ij (t _m ) = D _yc , τ _Fij <t _m <τ _Fij +τ _Oij ; In step 4, the thrust shutdown model is: Through the thermal test of the power system, the statistics show that the thrust shutdown model of the target 2 thrust engines with a total of 6 thrust gears is:

In the above formula, T _Cij is the theoretical thrust, τ _Fij is the closing response time of the solenoid valve, which is consistent with the opening response time of the solenoid valve, τ _Cij is the time for each thrust to drop from 100% to 0, where i represents the engine serial number, and j represents the thrust Gear number, for example, T _Cij is the first thrust gear of the first engine, that is, T _1c1 = 600N; It can be seen from the above formula that within the time τ _Fij after the engine is turned on, the solenoid valve is opened to close, and the thrust during this period is the theoretical thrust T _icj ; within the time τ _Fij +τ _Cij , the engine thrust gradually changes from the theoretical thrust Decrease to 0, in this interval, the speed change trend of the target is to increase first, when the target T _Gij (t) is equal to the resistance D _b at the current moment at time t, the speed of the target begins to decrease gradually; therefore, if the engine is at When the upper threshold Ma _Poff is turned off, the cruise speed of the target will be greater than Ma _Poff during the thrust shutdown process; in order to improve the control accuracy of the cruise speed, the shutdown threshold value is corrected as follows: Ma′ _Poff ＝ Ma _Poff -δ _Moff (7) In the above formula, δ _Moff is the correction value of the lower limit of speed control, and the calculation method is as follows:

In the above formula, the thrust T _Gij (t _n ) at time t _n = D _yc , τ _Fij <t _n <τ _Fij +τ _Cij . 2. a kind of supersonic large maneuvering target according to claim 1 is based on the high-precision speed control method of pseudo-closed loop, it is characterized in that: parameter selection is: H _c =9000, Mac ₌ 1.2, σ _Ma =0.05, recommended The predicted resistance D _yc of the target is obtained by the model = 2200N; therefore, the strategy (2) is selected, and the thrust combination of 1200N+2800N is selected for the gear position, so the relevant parameters are selected as: τ _F23 = 0.04s, τ _O23 = 120ms, τ _C23 = 100ms, T _C23 = 2800N, from which Ma' _Pon = 1.153, Ma' _Poff = 1.248.

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